Duplex steam-pump.



S. DIDRICHSEN.

DUPLEX STEAM PUMP.

APPLICATION FILED MAR.29, 1915.

1,21 1 ,686. Patented Jan. 9, 1917.

a snzns-suzn 1.

Inv E ntu I":

3.1] idr'ichs en Att 2: rneg S. DIDRICHSEN.

DUPLEX STEAM PUMP.

APPLICATION men mums. 1915 1 21 1 ,86 Patented Jan; 9, 1917.

3 SHEETSSHEET 2- I IE? Inventor:

Sjlirlr-ichsen Att urnay Witnesses:

S. DIDRICHSEN.

DUPLEX STEAM PUMP.

APPLICATSON men MAR.29- 1915.

Patented Jan. 9, 1917.

3 SHEETS-SHEET 3.

Invsntnr Slliflrinhs an Attorney @FFIQE.

SIGVART DIDRICHSEN, OF SKtlIEN, NEAR GHRISTIANIA, NORWAY.

DUPLEX STEAM-PUMP.

Specification of Letters Patent.

Patented J an. 9, 1917.

Application filed March 29, 1915. Serial No. 17,820.

To all whom it may concern:

Be it known that I, SIGVART DIDRIGHSEN, engineer, subject of Norway, residing at Sktiien, near Christiania, Norway, have invented new and useful Improvements in Duplex Steam-Pumps, of which the following is a specification.

It is a well-known fact that the usual duplex steam pumps have two steam cylinders with a distributing slide for each cylinder, arranged in such a manner that the one piston moves the slide of the other piston, and vice versa. From the slide-face two channels pass to each side of each piston, one,

channel being for admission of fresh steam and the other being for exhaust of the utilized steam.

In order to prevent the pistons from striking against the cylinder heads each piston, when approaching the end of its stroke, closes the exhaust channel of its own cylinder, whereby some steam is inclosed which is compressed and acts as a steam cushion. But as the degree of compression must be arranged so high that the pistons do not strike against the heads, even if the pump operates at a very high velocity or with a high steam pressure, it is obvious that the pump at less steam pressure and normal velocity is not able to compress the steam cushion to the same extent. The consequence is that the pump shortens its stroke and works with an unproportionately large noxious space, and at the same time its yield is decreased. As the steam piston, as mentioned above, does not move its own slide. because the latter is moved by the other piston, the admission channel is left open until the other piston has nearly completed its stroke, which condition causes a still more increase of the steam-consumption on account of condensation. In addition hereto, nothing of the expansion effect of the steam is utilized.

The object of my present invention is to remove these drawbacks and thereby to provide a pump, which is more economical in operation than the duplex steam pumps hitherto in use.

A construction for carrying out the invention is shown in the accompanying drawing, in which:

Figure 1 is a longitudinal section through one of the steam cylinders with appertaining cylindric slide and moving device for the same. Fig. 2 is a plan view showing a longitudinal section through the slide casing and the slide arranged therein and also its moving device. One half of the slide is shown in longitudinal section. Fig. 3 shows, at one side of the middle line, a section along the line czb of Fig. 1 and at the other side a section along the line 0(Z of Fig. 1. Fig. 4 illustrates the moving device proper for the two slides, and Figs. 58 show four different slide positions.

The steam piston -1 in Fig. 1 is for the steam cylinder 2 which is shown in section and which is connected at either end with the slide casing 3 by means of the channels 4, 5. The steam piston 6, which is shown in dotted lines, is for the twin-cylinder, which in similar manner is connected with the slide casing --3 through the channels 7, 8 (see Fig. 2).

In the slide casing 3 is arranged a cvlindric slide or valve 9 so constructed that it, during rotation, connects alternately the channels 4, 5, 7- and 8 with the steam inlet 10 or with the outlet opening -'11. As seen in Figs. 2 and 3 the one space D of each slide half is constantly in connection with the inlet 10 and the other space A is constantly in connection with the outlet -11. The spaces D and -A in the two slide halves are angularly displaced an amount of 90 degrees in relation to each other as seen from the dotted lines in Fig. 1.

A stepwise rotary movement is imparted to the slide, always in the same direction see arrows in Figs. 4-8) in such a manner that it stops in the four main positions X, Y, Z, U in Fig. 4. This rotary movement is imparted to the slide 9- by the reciprocating piston rods 12, 13- by means of a clutch piece 14, 15 attached to either of them, and connecting rods 16, 17, which are further connected to the slide 9 by a crank lever 18 19 attached to either end pin of the slide.

For better understanding the distribution of the steam, Fig. 5 shows the slide position corresponding to the positions X and -U (Fig. 4) of the crank' levers .-18 and -19 respectively. Figs. 6-8 show the slide position after each succeeding rotation of 90 degrees of the said levers. The large arrow in these figures indicates the rotating direction of the slide. In Figs. 5 and 7 the less arrows indicate the direction of the 1 steps, each amounting to 90 degrees.

steam and exhaust in the channels L and 5. In Figs. 6 and 8 these channels are closed and the dotted arrows indicate the direction of the steam and exhaust in the rearwardly locating channels 7 and The movement and the steam distribution takes place as follows: At the slide position shown in Fig. 5 the piston ,1- moves in the direction of the arrow (to the right) and pulls by means of the clutchpiece 1 l the connecting rod -16 along with it, whereby the latter imparts through the lever -18 a rotation to the slide 9-, so that the same in position figure 1 just begins to place the channels 7 and 8 in connection with the steam inlet *-10- and the outlet opening -11- respectively, whereby the pistony6 is reversed and moves in the same direction as the first one. Directly thereafter the slide -9 cuts off the admission of steam through the channel and the steam lmoves further by the expansion of the steam. When the piston 1- now approaches the end of its stroke, it has further rotated the slide 9 so that it closes the outlet through the chan nel 5, and the steam thereby inclosed is compressed so as to finally stop the piston 1. The latter then has completed one stroke and during this rotated the slide an angle of 90 degrees. The slide now occupies the position shown in Fig. 6. In the meantime the piston 6 continues its movement (to the right) and the clutch-piece -15 arrives in contact with the stop 22- on the connecting rod 17 so as to pull the latter along with it, whereby the slide 9 is rotated through the lever -19 and is connecting the channel 5 with the inlet opening -10- and the channel 4 with the outlet opening 11. Hereby the piston l is reversed and moves in the oppo site direction (to the left) of that indicated by the arrow in Fig. 1. During the further rotation of the slide 9 the admission is cut off through the channel -7 and the piston 6 moves farther by the expansion, whereupon the outlet through the channel 8 is closed, the compression begins and the piston 6 stops (slide position Fig. 7). tinues its return stroke (to the left) and reverses in the same manner the piston 6, and its own steam cylinder inlet and outlet are closed (slide position Fig. 8). The piston 6 then completes its return stroke, during which the piston 1 is reversed and its own cylinder inlet and outlet are closed (slide position Fig. 5). Thus one stroke cycle of one forward and one return stroke of each piston 1- and 6 is complete, and the slide -9 has been caused to rotate one complete revolution in four The piston 1 then con- The moving mechanism is shown especially in Fig. 4'. The clutch-piece 14.- moves to the right and has just arrived in contact with the, stop20 on the slide bar 16- and pulls the same along with it. Thereby the crank lever 18 is also pulled from X to Y and the lever 19- attached on the other pin of the slide follows with it from U to X. The clutch piece -15- now is moving to the right, and when it has arrived in contact with the stop 22- on the slide bar -17%, the lever 19 is pulled from X to -Y- and lever 18] follows with it from Y to Z. The piece -14E now travels to the left, and when it has arrived in contact with the projection -21 on the slide bar 16, the lever 18' is forced from -Z to U and the lever 19 follows with it from -Y' to' Z-.

Finally the piece 15- on the slide bar 17- travels to the left and forces the lever 19 from Z to 'U, and the lever -18 follows from -U to X. The both levers 18, 19 now again occupy their respective initial positions, and the slide 19 has made one complete revolution in the direction of the arrow.

In order that the pistons may beable to make full strokes at any velocity and pressure-conditions it is necessary to be able to control the degree of expansion and com pression. This is obtained by such an arrangement that the levers 1 8, 19 can alter their position in relation to the slide 9-. A construction for realizingthis purpose is shown in the drawing, the pins of the levers -18, 19 being adjustable within the rectangular slots -2land -25.. If now the pump makes too short strokes the pins of the levers 18, 19 are displaced within the slots 24:, 25* in the same direction as that. in which the slide 9-- rotates, whereby the degree of expansion and compression is decreased, and on account hereof the pump must make longer strokes. But if the pistons strike against the cylinder head, the pins of the levers 18, 19- are displaced in opposite-direction to that of their rotation, whereby both the expansion and the compression are increased.

Briefly stated, the invention above de scribed is characterized by the piston rods imparting during their reciprocating movement a rotary movement alternately to a cylindric slide (double slide) common to the both steam cylinders.

Having now described my invention, what piston rods for said cylinders; alined rotary slide casmgs having their mutual axis ar-' ranged transverse to the cylinder axes; chan-i nels passing from the end spaces of the cylinders to respectively opposite sides of the respective alined casings; a rotary slide comprising a pair of rigidly inter-connected rotary members adapted to rotate in a constant direction by increments of 90; crank levers secured to said slide 90 apart in angular relation to each other; clutch pieces on each piston rod respectively; and connecting rods one between each clutch piece and its corresponding crank lever.

2. In a duplex steam pump, the combination of a pair of cylinders; pistons therein; piston rods for said cylinders; alined rotary slide casings having their mutual axis arranged transverse to the cylinder axes; channels passing from the end spaces of the cylinders to respectively opposite sides of the respective alined casings; a rotary slide comprising a pair of rigidly inter-connected rotary members adapted to rotate in a constant direction by increments of 90; crank levers secured to said slide 90 apart in annular relation to each other; clutchpieces on each piston rod respectively; connecting rods, one between each clutch piece and its corresponding crank lever; and a tangentially adjust able connection between each connecting rod and its corresponding crank lever for adjusting the cut-0E position of the slide relative to the piston position.

3. In a duplex steam pump, the combination of a pair of cylinders; a piston in each cylinder; a slide casing having feed and exhaust channels communicating therewith the axis of said casing being arranged transverse Copies of this patent may be obtained for to the cylinder axes; a rotary double slide adapted to rotate in a constant direction in said casing; and comprising a pair of members each having approximately oppositely disposed connecting spaces connecting with the feed and exhaust channels respectively; crank levers secured to said slide 90 apart in annular relation to each other; channels connecting opposite ends of the cylinders with the opposite sides of the slide casing and adapted to register with the connecting spaces of the respective members of the rotary slide, the relative arrangement of the channels and spaces being such that the feed andexhaust are cut off from one cylinder while connected to the opposite ends respectively of the other cylinder; and means connecting each crank lever to the piston of the corresponding cylinder for causing one member of the slide to cut 011' the feed and exhaust of such cylinder when the piston reaches the end of the stroke, while the other member of the slide connects the feed and exhaust to opposite ends of the other cylinder, the relation of said connecting spaces being such that the feed is out off before the exhaust is closed in order that the steam inclosed within the cylinder may expand.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

SIGVART DIDRICHSEN.

Witnesses AxnL LAHN, MOGENS Bnecn.

five cents each, by addressing the Commissioner of Patents,

Washington, D. G. 

